1. Field of the Invention
This invention relates in general to hydraulic couplings, and specifically to hydraulic couplings used in undersea drilling and production applications. More particularly, this invention involves a female hydraulic coupling member having recessed flow passages that facilitate connection to male coupling members.
2. Description of Related Art
Subsea hydraulic couplings are old in the art. The couplings generally consist of a male member and a female member with sealed fluid passageways connecting therebetween. The female member generally is a cylindrical body with a relatively large diameter longitudinal bore at one end and a relatively small diameter longitudinal bore at the other. The small bore facilitates connections to hydraulic lines, while the large bore seals and slidingly engages the male member of the coupling. The male member includes a cylindrical portion at one end having an outer diameter approximately equal to the diameter of the large bore of the female member of the coupling. The male member also includes a connection at its other end to facilitate connection to hydraulic lines. When the cylindrical portion of the male member is inserted into the large bore of the female member, according to various embodiments of the device, fluid flow is established between the male and female members. Couplings of this type are shown in U.S. Pat. No. 4,694,859 to Robert E. Smith, III and other patents owned by National Coupling Company, Inc. of Stafford, Tex.
In undersea drilling and production applications, the male member of the coupling may be connected to a manifold plate or other securement at a subsea location at the inside or outside of a well bore. The female members, which also may be secured to a manifold plate, are moved into position over the male members and then lowered onto the male members by a diver or subsea vehicle. When the female members are positioned on the male members, hydraulic fluid flow typically is from the female member to the male member of each coupling. In some cases, only the female member of the coupling has a poppet valve.
The poppet valve typically includes a conical valve face which seats, in the closed position, against a valve seat in the coupling member. The poppet valve opens to allow fluid flow, and closes against the valve seat within the bore to arrest the flow. Generally, the poppet valve is spring-biased to the closed position. The valve may include a valve actuator which may be a nose or stem extending from the apex of the valve face along the longitudinal axis of the poppet valve.
In the couplings of U.S. Pat. No. 4,694,859, for example, hydraulic fluid flows longitudinally between the male and female coupling members. A number of different improvements and variations have been introduced in the configuration of flow ports and flow passages in couplings used for undersea applications. Some undersea hydraulic couplings are pressure balanced, for example, which may be achieved by hydraulic flow through aligned radial flow passages in the coupling members. The radial flow passages are generally perpendicular to the longitudinal axis of the coupling, so hydraulic pressure tending to separate the coupling members is significantly reduced. In the male coupling members, radial passages typically extend from the central bore outward to the cylindrical outer surface of the probe. Examples of pressure balanced couplings are shown in U.S. Pat. Nos. 4,754,780, 5,099,882, and 4,832,080 to Robert E. Smith III, assigned to National Coupling Company, Inc.
Male undersea hydraulic coupling members also may include flow ports that are angled to prevent ingress of debris when the coupling members are disconnected. Frequently, well bores in which the couplings are positioned are full of debris. The male member, which remains subsea when the coupling is disconnected, is subject to debris accumulating in flow passages. The debris may contaminate the hydraulic fluid or cause wear to the seals and sealing surfaces in hydraulic couplings and hydraulic systems. To reduce or eliminate this problem, couplings such as those of U.S. Pat. No. 5,692,538 to Robert E. Smith, III have utilized angled flow ports that prevent ingress of debris into the hydraulic lines.
In the past, each of these male coupling members could be effectively connected only to certain female coupling members. For example, pressure balanced male coupling members with radial flow passages could only be connected to female coupling members having matching radial flow passages. Male coupling members with angled flow ports could be connected to conventional female coupling members configured for longitudinal flow of hydraulic fluid, but hydraulic flow between the angled flow passages, through the annulus between the male and female members, and the female member, was somewhat reduced. Accordingly, a female coupling member is needed to be connectable to a variety of different male coupling members without significant reduction in the flow of hydraulic fluid or other performance degradation.
The present invention resides in a female undersea hydraulic coupling member having recessed flow passages to facilitate flow of hydraulic fluid with male coupling members having flow passages that are either longitudinal, radial or angled. The recessed flow passages in the female coupling member allow interconnection with various different male member flow passage configurations without significant reduction in volume or flow rates. The recessed flow passages are machined in the body section of the female member.